Carburetor



Oct. 6, 1942. I 2,297,736

CARBURETOR Filed July 11, 1941 2 Sheets-Sheet 2 Hm I I!!! llll l1 INVENTOR. A NTHONY A YMAE.

A T TORNEYS Patented Oct. 6,1942

UNITED STATES PATENT OFFICE CARBURETOR Anthony Aymar, New York, N. Y. Application July 11, 1941, Serial No. 401,937

1 Claim. (Cl. 261-51) This invention relates to fuel atomizers or carburetors for internal combustion engines.

An object of the present invention is the elimination of fuel pumps, accelerating jets, check valves, idle jets, idle screws, vacuum pistons, float chambers, float and fuel valves and similar devices used in existing carburetion systems by the provision of a carburetor wherein fuel is drawn directly from the source of supply by vacuum created in a discharge pipe or nozzle and is mixed with air to form a combustible mixture.

Another object is the provision of a carburetor which is of simple construction, efficient in operation and inexpensive to manufacture.

Other objects will becom apparent in the course of the following specification."

In accomplishing the objects of the present invention, it was found desirable to connect the source of fuel directly with a metering needle valve operated by the throttle valve of the engine, th amount of air mixing with the fuel being automatically regulated by a resilient diaphragm which is operated by suction or press ure'difference to vary the operative area of the airpassage, so that auniform ratio of fuel and air is maintained throughout the entire range of speeds of the engine.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings showing, by way of example only, preferred embodiments of the inventive idea.

In the drawings:

Figure 1 is a vertical section through a carburetor constructed in accordance with the principles of the present invention.

Figure 2 shows in section and on an enlarged scale the fuel control mechanism of the carburetor.

Figure 3 is a top view of the carburetor.

Figure 4 is a transverse section along the line 4-4 of Figure 1. I

t Figure 5 is a top view of a diaphragm.

Figure 6 is a section along the line 6-6 of Figure 5, on an enlarged scale. 7

Figure 7 is a perspective view of; one of the blades of the diaphragm.

Figure 8 shows in side elevation a somewhat differently constructed carburetor.

Figure 9 is a section along the line 9-9 of Figure 8.

The carburetor shown in Figures 1 to 4 of the drawings includes a carburetor body or casing ll having the form of a pipe provided with an upper air inlet opening l2 and a lower flange I3 (Figure 1).

The fuel is supplied from a tank [4 through a supply pipe l5 which-is connected in a fluid-tight manner by a threaded stufiing box IS with a boss or tube 11 which is integral with the body H. A thicker wall l8 of the body ll encloses a passage 9 which is in communication with the tube I1 and the pipe I5, and which leads to a chamber 20 formed in a boss 2| which is also integral with the body II.

The boss 2| contains a needle valve regulating may be conveniently varied in relation to the valve seat, constituted by a restrictor or sleeve 28 which is screwed into an opening formed in a wall of the body II and extending between the interior of the body II and the chamber 20.

A fuel control member 29 has one end engaging the sleeve 2.3 and fitting into a recess formed in an inner surface of the body II. This part of the member 29 has the form of a tube enclosing a passage 30 which may communicate with the chamber 20 through the restrictor 28.

Another part of the membe 29 has the form of a solid pin and is engaged by a distancing screw 3| situated within a threaded hole 32 of the body II and used to maintain the member 29 in position Within the body I I. The central part of the member 29 consists of an upwardly extending tube or sleeve 33 and a downwardly exfor the metering needlevalve. The sleeve 33 and the tube 34 have the same central axis extending at right angles to the longitudinal axis of the member 29. Thesleeve 33 has inner and outer screw threads and is covered by a cap 35 screwed upon the outer screw threads of the sleeve 33. The lower end of the tube 34 is threaded and carries an elongated downwardly extending fuel discharge pipe or nozzle 36 which is suspended from the tube 34. v

The inner screw threads of the sleeve 33 are used to hold a hollow member 31 carrying a seat 15 of the metering needle valve (Figs. 1 and 2). The-member 31 has the form of a cylindrical body having an inner chamber 38 which communicates member 31 and situated opposite the opening 39.

The valve body of the metering needle valve consists of a long tapered end 43 of a needlebody 44 the lower end of which is pivotally connected at 45 to the carburetor throttle plate 46. The throttle plate 46 is swingably mounted in a tubular lower casing 41, the opening 48 of which leads to the intake manifold of the engine. The throttle valve is of standard construction and is not illustrated in detail in the drawings.

A union 49 is screwed upon the upper end of v the casing 41 and is used to connect the casing 4I with an intermediate casing 50, a gasket I being interposed between the casings 41 and 50 to provide a fluid-tight connection. The casing 50 has a flange 52 whichisconnected with the flange I3 of the casing II by the bolts 53. The use of the union 49 makes it possible 'to adjust the position of the casings II and 50 in relation to the lower casing 41. v

The diaphragm 54 (Fig. 5) consists of a plurality of resilient substantially radially disposed blades 55 made of spring steel or other suitable material and partly overlapping each other to' form a Venturi-like structure.- As shown in Figure 7, each of the blades 55 has an inner edge 56 which is so curved that the overlapping edges 56 of all the blades '55 form a round edge portion situated around the pipe 36 and enclosing an annular passage 51 for the inflowing air.

The outer edges of the blades 55 are provided with downwardly extending flanges 58 fltting into an annular groove provided in a blade-holding ring 59.

The diaphragm 54 may be manufactured by arranging the blades 5-5 in the proper manner with their flanges 58 in the groove of the ring 59 and by pressing then a flange 60 of. the ring 59 from a position shown in full lines in Figure 6 to a position shown therein by broken lines. The flange 60 .then covers the flanges 58 of the blades 55 which are firmly clamped by the ring 59.

As shown in Figure 1, the ring 59 holding the blades 55 is firmly clamped between the flanges I3-and 52 and is situatedin recesses formed in these flanges The inner surfaces of the casing II and 50 adjacent to the blades 55 include recessed curved, portions 6| and 62, respectively, which permit the blades 55 to move outwardly or inwardly from their normal horizontal position to positions shown by broken lines, thereby,

In operation, as the engine is started by hand or by a. starter, air is drawn through the opening I2 in' the .direction of the arrows 69 inside the casing II. The air will flow around the fuel control member 29 and through. the narrow passage 51 between the pipe as and the diaphragm 54 which is then situated in the position shown by full lines in Figure l. The flow of air around the pipe 36 and through the opening 64 of the plate 63 will create suction at the lower end of the pipe 36, which is further intensified by the action of the engine. This suction causes a flow of fuel from the supply tank I4 and through the pipe I5 and the passage I9 to the chamber 20.

The needle valve 22 is used to limit the maximum amount of .fuel passing through the restrictor 28 and may be'convenientiy adjusted by turning the knob 24 to adapt the carburetor to various individual requirements.

The fuel 'flows from the chamber 20 and through the restrictor 28, the passage 30 and the opening 39 into the chamber'38. Thence it flows around the metering needle valve 43, 44 and through the passage and the nozzle or pipe 36. As the fuel leaves the lower end of the pipe 36,-it is mixed with air which is flowing past it, so that a combustitble fuel air mixture is formed which is carried to the engine in the direction of the arrow 10. I v

As the throttle is opened wider and the throt-j .tle plate is turnedin the direction of the arrows II, the needle 43, 44 of the metering valve ismoved downward due to its connection at 45 with the throttle plate 46, thereby increasing the operative cross-sectional area of the passage 40, so that more fuel is drawn in proportion to the air entering the carburetor. The increase of the area available for the passage of air, which is caused by the turning of the throttle plate 46, will increase the pressure of the flowing air upon the diaphragm 54, so that the blades of the diaphragm will be pressed downwardly and outwardly, thusincreasing the area of the passage 51 between the edges 56 of the blades 55 and the nozzle or pipe 36. Thus more air will flow through the passage 51 and be mixed with the fuel leaving the pipe 36.

It is thus apparent that an increase in the amount of supplied fuel will be followed automatically by an increase in the amountof air,

so that a uniform ratio of fuel and air is main-' tained in the combustible mixture throughout the entire range of speeds. The proportion of supplied gas is affected by the tapered metering valve needle 43 which moves up and down in the passage 40.

In case of a backfire of the engine. the blades 55 of the diaphragm 54 bend inwardly or upwards, so that the diaphragm will not be dam aged by. thebackflre.

The described carburetor is of simple andv sturdy construction and it effectively'eliminates the necessity of using fuel pumps, float chambers and valves, and many other parts. since fuel is drawn directly from the tank I4 due to the suction or vacuum created in the discharge pipe or nozzle 36.

The carburetor shown in Figures 8 and 9 in cludes an upper casing or carburetor body III having alower flange II3 which is permanently connected with a flange I52 of an intermediate casing I50 by a clamping ring I53. The carburetor is supplied with fuel through a pipe II! The fuel control member, the metering needle valve and the fuel discharge pipe ill are of the same construction as those previously described. The lower casing Ill of the carburetor comprises a flange II which is connected with the flange ll of the intermediate casing III by bolts 0. Thus the casings}! II and ll. may be conveniently adjusted in relation to the lower casing Ill.-

The diaphragm III is held between the flanges ill and ill and the do'wnwardmovement of its blades is stopped by an annular plate (not shown) which is held within the intermediate casing in by a screw I. The throttle valve plate (not shown) which is situated within the lower casing I" is operated by a leverage system If.

The operation of this carburetor is the same as of that illustrated in Figures 1 to 4.

It is apparent that the specific illustrations described above have been given by way of illustration and not by way of limitation, and that the shown structures are subject to wide variation and modification without departing from the scope or intent of the present invention. All of such variations and modifications are to be included within the scope of the present invention.

What is claimed is:

In combination with a fuel tank and a throtflow of air, a diaphragm having the form of an I annular plate consisting of resilient blades situated within said casing and extending transverseLv thereto, said resilient blades being bendable in two opposite directions in relation to said fuel discharge pipe to vary the area of a passage for said flow of air between said blades and said fuel discharge pipe, a valve in said fuel control member, means connecting said valve with said throttle valve plate, whereby said valve is actuated by said throttle valve plate, and a stop member situated within said casing be.- tween said diaphragm and said throttle valve plate and having surfaces adapted to be engaged by the bent resilient blades to prevent further bending of said blades.

ANTHONY AY'MAR. 

